A lot of advanced western bottle collectors admire and talk about the sparkling, beautiful fire aqua coloration of western manufactured glass, but that wasn't always the case. When the two most successful glassworks were starting out in San Francisco, the raw ingredients that were being used came mostly from various parts of California, with some experimenting being done along the way to come up with good working formulas of ingredients that could be had locally without incurring substantial expense of having to import them. Eventually it was found necessary to import some of the ingredients to get the quality of glass desired.
In the earlier years for the commoner glass, the glassworks would use sands from the North Beach area of S.F. as well as the surrounding hills, along with sand from the Oakland side of the bay. This sand was coarse and not free of iron oxides. Along with glass blowers of limited experience and various skill levels bottles were often made with what I call "in manufacturing flaws", these are often referred to as bruises, crazing, flashes, fractures, etc. They are in reality the result of poor manufacturing process and or annealing process.
Another effect that occurs on early western glass is devitrification, this is caused by the glassblower reheating the glass too often to finish it, causing the crystalization of the surface of the glass, both inside and or outside. This condition is sometimes mistook for haziness or staining in the glass. Examples of this are seen on variant 1 & 2 Lacour's, variant 1 Cassin's and variant 1 Dr. Henley's bitters.
Here is an example of a early western blown variant 1 Rosenbaums Bitters bottle, when placed in a window sill with light, it is easily seen with several in making flaws. Most likely these large western examples were blown during the 1866-67 time frame.
Friday, October 2, 2009
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Great topic Warren. Why do you think that much of the lighter green 1860s western glass often has several flashes ?
ReplyDeleteWarren:
ReplyDeleteIs this the large square Rosenbaum's I sold you years ago? It kinda looks like it but I remember it having more green.
Aside from annealing cracks most of that crystallization, haziness or staining that your referring to is post manufacturing caused by ultraviolet light exposure (sunlight)or "UV Crazing" as I call it. For some unknown reason we typically only see this in Western blown bottle glass from about 1866-1888. The problem was worse is the 60s and eventually refined but the late 80s.
The one thing you should NEVER do is place one of these early Western blown pieces with this tendency in direct sunlight for any length of time, you'll ruin it. Just even in the matter of a few hours the glass can start to transform into that crystallized effect. If you look at this phenomena under strong magnification it looks like millions of tiny shatter cracks/crazing.
Years ago I dug a beautiful mint apple green Lacour's. Within two hours of coming out of the ground and being exposed to light and a warmer climate it developed hundreds of cracks. I can only attribute this to two things, exposure to light and temperature change, this glass is extremely fragile.
When we dig anything like that now it immediately gets buried/packed in a bucket full of dirt from the hole. The bucket with the bottle buried inside it allowed to sit for at least a week in a cool spot to acclimate. This method is our standard procedure on all better Western pieces that may have this tendency.
G.P. You are absolutely correct about that old pre 1880s glass, especially the older stuff from the 60s 70s. I had a beautiful Dr Henleys that came out of old Sacto that cracked and almost fell apart in only a couple hours in the heat and sunlight , it was summer in the city. and destructo for the bottle......Andy
ReplyDeleteAdding a little to GP's comments:
ReplyDeleteI am also familiar with the phenomenon of which he wrote. I call it 'cancer glass'. The outer surface of the bottle when subjected to the rays of the sun (UV)develops a scaley surface upon first noticing the change. Looks like stain at first. Upon closer viewing, it becomes apparent that the reaction is inside the glass as well and appears internally as thousands of tiny refractions. This effect gets worse and worse the longer it is in the sun, until the glass becomes almost non-transparent.
Through experimenting with broken Western-blown bottles in the sunlight placed under different reflective magnifications, I have determined that this reaction will not occur most of the time. I have concluded that it occurs only in bottles in which the glass has been mixed or treated improperly at the Glassworks. Even though those are good odds in favor of the collector, it is basically impossible to know this until the reaction either happens or doesnt to your shard or bottle. I also have noticed, if it is going to occur, it's usually during the first exposure. An on the vehicle dashboard exposure turned out to have the quickest harsh reaction. In a matter of several hours, a broken Van Bergen went from shiney sparkle glass to full-on scaley refracto cancer glass.
I have also seen mild cases where I have dug a bottle, wrapped it immediatley in newspaper, let it sit in the paper for a few wks before washing, and still had the refractive internal crystalization throughout the entire bottle but not the scaley exterior. So, it is also possible that exposure to oxygen also is a trigger, but much much slower than the UV/Oxy combo.
So, bottom line, like he said... don't chance it with putting the good Western bottles in the sunlight, especially if it is one that has been recently dug, where the odds are it has never been exposed and possibly could be cancer-glass.
All good points made by Dr. AP. It's also possible that the refractive internal crystallization throughout an entire bottle even though wrapped in newspaper may also suggest another theory. Are you sure AP being how the bottle was dirty that it didn't have the crystallization before you wrapped it ? What if the bottle was exposed to an amount of sunlight before it was tossed down some dark hole some 130 years prior? It's hard to determine exactly what kind of Western blown glass bottle will react this way but the late 60s bitters seem to be the most venerable, especially shades of yellow green.
ReplyDeleteI have noticed this only happening on amber or olive colored glass. What colors have you guys seen it happen to ?
ReplyDeleteIn my research of what causes this anomaly is the use of a poor type of soda or a substitute. The early glass works were using both a carbonate of soda or a sal soda compound, sometimes even the refuse of a nitre of soda from the local chemical works. It is the use of one of these compounds that is causing this effect.
ReplyDeleteI've seen this condition in amber, olive, yellow-green colors.
This is a Dr. Barnes test
ReplyDeleteanother test
ReplyDeleteSorry for all the Test Comments, I had to figure out what box needed to be unchecked in Mozilla to continue on. All Better Now, I don't feel so much like an R - Tard. Sheese!
ReplyDeleteI have noticed that on certain types of bottles in greens, there seems to be a lot of flashes and checks, such as on Jakes and J.Walker V Bitters, I don't see them on my green flask or spices though. Must be just poor quality sand used in the making of the glass?? Dr.Barnes
Good point GP. We surely dont know how much exposure a bottle has had before being consumed and tossed into a hole.
ReplyDeleteWarren, I think you are definetly on the right track, that it is improper mixing of the compounds or not using the correct element.
Andrew, it happened on a Western blown cobalt Wakelee's Cameline that I dug w the S.D boys yrs ago. So, I've seen it occur on blue, ambers, and shades of green glass. I've only seen it happen on glass blown from approx 1865-1885.
Dr Barnes, the flashes and checks you mention are a different glass house defect, caused from poor annealing. And yes, you are correct, greens seem to be most commonly seen w this 'flashing/checking' problem, especially bottles from the 1860s. Most green spices are 1870s, and the problem was less prevalent at that point. It's possible that since it required different chemicals/elements to make different colors of glass, these may have reacted differently (eg: blue Fonsecas and green Lacours) and needed higher or lower annealing temperatures or longer/shorter annealing times. By the mid to later 1870s the SF glasshouses seemed to have worked-out the kinks in the process and the annealing checks rarely show-up in places other than the neck of the bottle and especially on bottles w narrower necks (eg: sodas, inks, and meds) possibly because the heat hung around longer in that area while trying to escape from inside the bottle. Kinda throwing out some ideas to consider here....
AP